Background/Rationale: People with serious mental illness (SMI) die, on average, many years prematurely, with rates of premature mortality 2 to 3 times greater than the general population. Over 60% of premature deaths in this population are due to natural causes, especially poorly treated cardiovascular, respiratory, and infectious diseases. Although the VA is a centrally organized, comprehensive healthcare system, veterans with SMI still have difficulty navigating the system, and are at substantially elevated risk for premature death. Too often, they do not attend scheduled appointments or fail to engage in primary care treatment, and consequently do not get valuable preventive and primary care services. Primary care in VA has undergone significant transformation under the Patent Aligned Care Team (PACT) model, which is based on the Patient Centered Medical Home (PCMH) concept. PACT has the goal of improving the quality, efficiency, and patient-centeredness of primary care. But it remains unclear how PACT will impact the large populations of veterans who get the majority of their care in specialty settings, such as people with SMI. Research can inform efforts to apply the PACT model in specialty settings. For example, while people with SMI do poorly with usual primary care arrangements, there is now substantial evidence that integrated care and medical care management approaches can improve medical treatment and outcomes, and reduce treatment costs, in people with SMI. Objective: Using available evidence, we propose to implement and evaluate a specialized PACT model that meets the needs of individuals with SMI (SMI-PACT). Methods: This project will partner with leadership at one medical center to implement SMI-PACT, with the goal of improving healthcare and outcomes among people with SMI, while reducing unnecessary use of emergency and hospital services. Evidence-based quality improvement strategies will be used to reorganize processes of care. In a site-level controlled trial, this project will evaluate the effect, relative to usual care, of SMI-PACT implementation on (a) provision of appropriate preventive and medical treatments; (b) patient health-related quality of life and satisfaction with care; and (c) medical and mental health treatment utilization and costs. The project includes a mixed methods formative evaluation of usual care and SMI-PACT implementation to strengthen the intervention, and assess barriers and facilitators to its implementation. Mixed methods will also be used to investigate the relationships between organizational context, intervention factors, and patient and provider outcomes; and identify patient factors related to successful patient outcomes. Significance: This project's approach to SMI-PACT is consistent with the VA PACT model, and with efforts in VA to improve care for veterans with psychiatric disorders. This will be one of the first projects to systematically implement and evaluate the PCMH and PACT concepts beyond primary care. Should SMI-PACT be demonstrated to be feasible and effective, the model could be used more broadly to improve the quality and efficiency of care for veterans with serious mental illness. Findings regarding PACT in specialty mental health may also inform efforts to improve care in other specialty healthcare settings.